This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Neuronal injuries induce profound changes in axons, dendrites, and synapses that usually lead to a devastating loss of function. While a large amount of research has broadened our understanding of axonal regeneration, very little is known about the ability of dendrites to regenerate after injury or denervation. Obviously, any successful clinical strategy will eventually need to consider the regeneration of dendrites and synapses if the full complexity of neuronal circuitry is to be restored. Thus, it is of great importance to understand dendritic regeneration and to identify factors that may be involved. The long-term goal of my research is to elucidate the factors which influence dendritic growth and plasticity. Specifically, work in my lab examines the compensatory regeneration of auditory interneurons in the cricket. Past research has demonstrated that unilateral removal of the ear in crickets induces denervated interneuron dendrites to grow across the midline, a boundary they usually observe, and form functional synaptic connections with the auditory afferents from the opposite ear (Hoy et al., 1985;Schildberger et al., 1986). This reinnervation is remarkably precise, reinstating interneuron-specific threshold and intensity responses. The central hypothesis of my research is that the compensatory regeneration and synapse formation of auditory dendrites in the cricket is guided by a recapitulation of the expression of developmental molecules. It is my hope that an investigation of this invertebrate regeneration phenomenon will advance our fundamental understanding of the plasticity of dendrites, and reveal principles governing dendritic regeneration that may be applicable to other neuronal systems.